

Firstly, exceeding the maximum allowable diameter of a brake drum can detrimentally affect the vehicle's braking performance. When the diameter is too large, the brake shoes may not make proper contact with the drum surface. This reduced contact area limits the friction generated during braking, which can lead to increased stopping distances—an alarming safety hazard in emergency situations. Moreover, improper brake drum size can result in uneven wear of brake components, leading to further complications and costs for maintenance.